package socket;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;

public class Server4 {//此版本用多线程来完成客户端和服务端的交互

    private ServerSocket serverSocket;
    //该集合用于保存所有客户端的输出流,用于广播消息.
    private List<PrintWriter> alllOut =new ArrayList<>();

    //ServerShocket的任务就是分配服务器端口
    public Server4() {//创建一个端口
        try {//
            System.out.println("正在启动服务器...");
            serverSocket = new ServerSocket(8088);//设置服务端端口
            System.out.println("服务器启动完毕");
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    public void start() {//这是自定义的start方法
        try {
            while (true) {
                System.out.println("等待客户端连接...");
                Socket socket = serverSocket.accept();//创建一个接收器
                System.out.println("一个客户端连接了...");
                //启动一个线程与客户端交互
                ClientHandler handler = new ClientHandler(socket);
                Thread t = new Thread(handler);
                t.start();//这个start()是Thread类下的方法
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        Server4 server = new Server4();//用于接收客户端的链接,并返回一个socket实例与客户端交互
        server.start();
    }

    private class ClientHandler implements Runnable {

        private Socket socket;
        private String host;//记录该客户端地址

        public ClientHandler(Socket socket) {
            this.socket = socket;
            host = socket.getInetAddress().getHostAddress();
        }

        @Override
        public void run() {
            try {
                InputStream in = socket.getInputStream();
                InputStreamReader isr = new InputStreamReader(in, StandardCharsets.UTF_8);
                BufferedReader br = new BufferedReader(isr);

                OutputStream out = socket.getOutputStream();
                OutputStreamWriter osw =new OutputStreamWriter(out,StandardCharsets.UTF_8);
                BufferedWriter bw =new BufferedWriter(osw);
                PrintWriter pw =new PrintWriter(bw,true);

                //将对应的客户端的输出流存入共享的allOut中,使得其他线程可以访问到
                alllOut.add(pw);


                String message;
                while ((message = br.readLine()) != null) {
                    System.out.println(host + "说:" + message);
                    //遍历allOut集合,给所有客户端发这个消息.
                    for(PrintWriter o:alllOut){
                        o.println(host+"说"+message);
                    }
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}


